Recently several reports have been presented stating that glandular kallikrein is present in human and animal blood, and that the oral administration of hog pancreatic kallikrein (HPK) normalises decreased urinary kallikrein and prostaglandin E₂ (PGE₂) excretions and elevated blood pressure in hypertensive patients.
In this study, HPK (2,000 KU/kg body weight) was intramuscularly injected into male rabbits, and several hormones (plasma kinins, plasma PGE, plasma 6-keto PGF_1α, plasma thromboxane B₂ (TXB₂), plasma renin activity (PRA), plasma aldosterone, plasma ACTH) were measured before and after HPK administration in order to clarify the role of glandular kallikrein in the blood.
Plasma kinins concentrations were significantly increased (the mean baseline level : 1 ± 1 pg/ml (mean ± S.E.), 30 min : 230 ± 22 (p<0.001), 60 min : 288 ± 36 (p<0.001), and 120 min : 130 ± 9 (p<0.001)) after HPK administration.
Plasma levels of PGE were slightly increased after HPK administration, but the change was not significant as compared with the mean baseline level.
Plasma levels of 6-keto PGF_1α were significantly increased from the mean baseline level of 229 ± 38 pg/ml to 594 ± 131 (p<0.05) at 30 min and to 378 ± 67 (p<0.01) at 60 min but were decreased to 278 ± 37 at 120 min after HPK administration.
On the other hand, the changes in plasma TXB₂, aldosterone and ACTH concentrations, and PRA were not significant before and after HPK administration.
From the present study, it was clarified that the exogenous intramuscular administration of HPK increased plasma levels of kinins and PGI₂, but induced no elevation in plasma levels of other hormones including PRA.

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Although angiotensin II, ACTH and potassium are generally acknowledged as major factors in regulating the influences on aldosterone secretion, it has recently been reported that dopamine is a potent inhibitor of aldosterone secretion in man and animals. In the present study, we investigated the effect of two kinds of dopaminergic receptor antagonists, metoclopramide and sulpiride, on plasma aldosterone concentration (PAC) and serum prolactin (PRL) in man. Normotensive volunteers and patients with hypopituitarism were injected with metoclopramide (10 mg i.v.) or sulpiride (10 mg i.m.). In normal volunteers, metoclopramide increased both PAC and PRL levels, and showed a maximum level at 30 minutes after injection. In patients with hypopituitarism, PAC tended to increase without change of PRL, which suggested that the increase in PAC by metoclopramide might have a direct inhibitory effect on the dopaminergic receptor in the adrenal gland. Moreover another antagonist, sulpiride also increased PRL but contrary tended to decrease PAC. These results suggested that PRL responses to both inhibitors were mediated by dopaminergic antagonist activity at the level of pituitary receptors. However dopamine-induced modulation of aldosterone secretion may be different from that of PRL at dopaminergic receptors. These results suggested that modulatory inhibition of aldosterone secretion by dopamine may be affected by difference of affinity of dopamine to receptor as organ specificity, or different affinity of metoclopramide and sulpiride to adrenal dopamine receptor.
In conclusion, dopamine antagonist metoclopramide increased both PAC and PRL level, but the other antagonist, sulpiride, increased PRL and tended to decrease PAC.

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Human chorionic gonadotropin (hCG) is a specific tumor marker glycoprotein hormone for trophoblastic diseases. It contains 4 asparagine-linked and 4 serine-linked carbohydrate units. Recently, variations in the carbohydrate moieties of hCG in choriocarcinoma have been suggested. However, the immunological method of detecting these malignant transformational changes of carbohydrate units in hCG have not been investigated. We therefore attempted to assess the possibility of establishing a radioimmunoassay system which can detect these transformational changes in serine-O-glycosidically linked carbohydrate units of hCG.
HCG-specific hCG β COOH-terminal portion contains all 4 O-glycosidically linked sugar chains (positions 121,127,132 and 138). An antiserum (R141) generated against the enzymatically cleaved, desialylated hCG β COOH-terminal peptide (residue 123-145) by toepad immunization method was extensively characterized. This antiserum reacts with asialo-hCG better than with native hCG. It does not bind with synthetic COOH-terminal peptides nor monosaccharides such as N-acetyl-D-galactosamine and D-galactose, which are sugar components in O-glycosidic carbohydrate chains. The HF-treated asialo-hCG, in which galactose residues are further removed, still reacts with the antiserum. The antiserum requires both the peptide sequence and N-acetyl-D-galactosamine residues for its binding. Glycophorine and fetuin, which also contain the same O-glycosidic carbohydrate structure, do not react with the antiserum. Beta subunit gains its binding capability to the antiserum only upon desialylation, while native a and 1 subunits do not react. The antiserum has high specificity toward asialo-hCG in which particularly O-glycosidic carbohydrate units are desialylated.
With a specific radioimmunoassay system using this antiserum (R141), urinary hCG preparations from 29 patients with various trophoblastic diseases were analyzed. Asialo-hCG immunoactivity was insignificant in all patients with hydatidiform mole, invasive hydatidiform mole and persisted trophoblastic disease. However, asialo-hCG was found in 2 out of 6 cases of choriocarcinoma. The existence of asialo-hCG may be related to the advancement of disease. Even though the actual etiology of choriocarcinoma is not well understood, the immunological detection of malignant transformational changes induced in carbohydrate moieties of hCG would be valuable for the early diagnosis of the disease.

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The heterogeneity of hPRL in the serum of a patient with a giant prolactinoma (hPRL 27 μg/ml) was studied employing gel chromatography, RIA and lymphoma cell bioassay. After gel filtration of serum sample on Sephadex G-100 (superfine) column, a few hPRL peaks were detected by RIA. Rechromatography of the second peak, which eluted between the void volume and the small third peak, revealed four hPRL peaks designated big-big hPRL, medium-big hPRL, big hPRL and little hPRL, with BA/RIA ratio 1.3-2.6, 0.8-1.2, 0.3-0.7 and 0.7-1.5, respectively. The molecular weight of medium-big hPRL was estimated as 80K-90K daltons. Most of big-big, medium-big and big hPRL were converted to little hPRL after mercaptoethanol treatment. These data suggest that most of big-big, medium-big and big hPRL are aggregates of little hPRL.

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To investigate the effects of bromocriptine on the secretion mechanism of pituitary gonadotropins and ovarian sex steroids, 5 mg of bromocriptine was administered to four normally cycling women in the follicular, pre-ovulatory, mid-luteal or menstrual phase, respectively. Blood samplings were taken from two hours before until six hours after the administration every 15 min. by an intravenous indwelling catheter. Serum FSH, LH, prolactin, estradiol and progesterone were determined by RIA, and the changes of basal levels and the pulsatile patterns of these hormones were analysed in each of the four phases.
Serum prolactin levels decreased significantly (p<0.005) from two hours after the administration of bromocriptine and remained in a very low range in all phases of the cycles until the end of the experiments. The basal levels of FSH showed a significant decrease in the pre-ovulatory and mid-luteal phases two to six hours after the administration (p<0.025-p<0.005). Also the basal levels of LH showed a significant decrease in the follicular, pre-ovulatory and mid-luteal phases two to six hours after the administration (p<0.05-p< 0.005). However, no significant change was observed in the amplitude or the frequency of the pulsatile patterns of FSH and LH in all phases of the menstrual cycles. The serum levels of estradiol did not show marked changes by the administration of bromocriptine, but the serum levels of progesterone were significantly decreased in the mid-luteal phase two to six hours after the administration (p<0.005). These facts suggest that bromocriptine acts mainly on the pituitary rather than the hypothalamus to decrease the serum levels of gonadotropins, and also may have some role in the steroidogenesis of the ovary.

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In order to clarify the intracellular localization of salivary peptide P-C like immuno-reactivity in the human pancreatic B-cells, an immuno-electronmicroscopical study using protein A-gold technique was carried out on the human foetal pancreas. Salivary peptide P-C like immunoreactivity was present in some of insulin secretory granules while insulin like immunoreactivity was found in all insulin secretory granules. The finding suggested that new substance in addition to insulin and its precursor was present in the insulin secretory granules of the human pancreatic B-cells. Furthermore, the finding seemed to explain the previous study that development of salivary peptide′P-C like immunoreactivity in the foetal pancreatic B-cells was immature in compared to that in the human adult pancreatic B-cells. In addition, to examine whether or not, salivary peptide P-C like immunoreactivity in the human pancreatic B-cells is Salivary Protein C, an indirect immunofluorescence technique using three kinds of antisera against salivary peptide P-C, Salivary Protein C and salivary peptide P-B, and using their antigens was undertaken on the adult pancrease. From the results of the study, it was thought that salivary peptide P-C like immunoreactivity in the human pancreas was neither Salivary Protein C itself, nor salivary peptide P-B itself, but was either salivary peptide P-C itself or unknown substance which had the common antigenic determinant with salivary peptide P-C, P-B and Salivary Protein C, since salivary peptide P-C like immunoreactivity in the human pancreas disappeared in the sections in which P-C antisera preincubated with each of salivary peptide P-C, P-B and Salivary Protein C were used as the primary antisera. Thus, although new substance was present in the insulin secretory granules of the human pancreatic B-cells, its pathophysiological role remained to be elucidated.

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Although several studies have been reported on the synthesis of steroids in the fetus, the metabolism and conjugation of estrogens in the fetus is not completely known.
In this study serum levels of estetrol (E₄), estetrol glucosiduronate (E₄4-G), estriol (E₃) and estriol-16-glucosiduronate (E₃-16-G) were measured by R.I.A. in maternal peripheral vein blood (MPV), umbilical artery blood (UA) and umbilical vein blood (UV) at delivery.
The same steroids were also measured in various fetal organs (liver, kidney, intestine, adrenal, lung and placenta) in the second-trimester.
After 4-¹⁴ C-E₂, 4-¹⁴C-E₃ and 6, 9 (n) -³H-E₄ were incubated with homogenates of various human fetal organs, the metabolites were analyzed with an authentic sample.
15, 15-D₂-estradiol-17β (d₂-E₂) was incubated with human second-trimester fetal liver and the metabolites were analyzed with GC-MS.
It was concluded that : 1) E₃-16-G was higher in UA and UV than in MPV, suggesting active glucosiduronation in the fetus. 2) Higher levels of E₄ and E₄-G in UA and UV than in MPV suggest the production of E₃ and E₃-16-G in the fetus. 3) Levels of E₄ and E₄-G were higher than those of E₃ and E₃-16-G in various fetal organs in the second-trimester. 4) E₄ and E₄-G were especially high in fetal liver and intestine, and E₃ and E₃-16-G were high in fetal kidney, liver and intestine. 5) The level of E₃-16-G was higher than that of E₃ in these organs. 6) The second-trimester fetal liver conjugated E₂, E₃ and E₄ to each glucosiduronate. 7) The second-trimester fetal kidney conjugated E₂ and E₄ to each sulfate, but E³ to E³-16-G. 8) 15-Hydroxylation of d₂-E₂ was demonstrated in the incubation with homogenate of second human fetal liver. 9) The active glucosiduronation of E₃ in the fetus was thought to inactivate a large amount of E₃ transported from the placenta.

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We studied the possible interplay between plasma bradykinin (P-BK) and the renin-angiotensin axis in essential hypertension, the effect of catecholamine on P-BK by standing and norepinephrine (NE) infusion, and the possible role of bradykinin in the hypotensive mechanism of angiotensin I converting enzyme inhibitor (captopril) in renin-independent essential hypertension.
Plasma bradykinin was measured by sensitive radioimmunoassay in 44 hypertensive patients and compared with that of 24 normotensive subjects. P-BK was not significantly reduced in hypertensive patients, and when subjects were divided by age range, the P-BK was reduced by aging in normotensive subjects but not in hypertensive patients, and the elder (60-80 yr) age normotensive group showed significantly (p<0.05) lower P-BK compared with the elder hypertensive aroup.
28 essential hypertensive patients (EHT) who were classified as WHO stagel (n=15) and WHO stagell (n=13) were given 80 mg of furosemide orally and kept upright for 4 hours. Plasma renin activity (PRA), P-BK, plasma aldosterone (P-Ald) and serum angiotensin converting enzyme activity (ACEA) were measured before and after furosemide administration. Twelve normotensive subjects served as controls. PRA, P-Ald and ACEA showed a significant increase (p<0.05) in all groups in response to furosemide. In normotensives, basal P-BK was 11.1 ± 1.3 pg/ml which increased to 15.6 ± 1.8 pg/ml (p<0.02) after furosemide. These changes of P-BK were in parallel with PRA, P-Ald and ACEA. In the WHO stagel EHT group, baseline P-BK was 9.7 ± 1.3 pg/ml which increased to 15.6 ± 1.8 pg/ml (p<0.02) and PRA, P-Ald and ACEA showed a similar increase as in normotensives. In the WHO stagell EHT patients, however, P-BK showed only a slight increase from 9.8 ± 1.0 pg/ml to 12.0 ± 1.1 pg/ml after furosemide. These changes were smaller either than normotensives or the WHO stagel EHT group. There was a slight but significant correlation between PRA and P-BK in normotensives and in the WHO stagel EHT. There was no correlation between PRA and P-BK in the WHO stagell EHT. The present results do not support the view that there may be a direct linkage between the kallikrein kinin system and the renin angiotensin axis mediated by kininase II or angiotensin converting enzyme in human peripheral blood. A blunted response of P-BK in WHO stage II EHT may suggest a secondary alteration of kinin metabolism in the development of hypertension.
Plasma norepinephrine (P-NE), P-BK and PRA were measured before and after 10 minutes standing, NE infusion (100 ng/kg/min) for 60 minutes in 10 normotensive subjects. Basal steady state P-NE (135 ± 12 pg/ml) rose to 279 ± 21 pg/ml and PRA also rose, but P-BK did not. Norepinephrine infusion increased P-BK from 13.3 ± 2.6 pg/ml basal to 22.3 ± 2.8 pg/ml (p<0.05) but did not increase PRA. This suggests that at the high extreme of the physiologic range (about 20-fold increase over supine basal), circulating NE caused a major change of P-BK.
The effects of a single administration of 100 mg captopril on P-BK in 34 EHT who showed agonistic responses to ¹ Sar, ⁸Ile-angiotensin II were studied. When the patients were analysed according to mean blood pressure (MBP) response, the responders showed a significantly greater P-BK increment (p<0.05), whereas the nonresponders did not show such an increase. There was a positive correlation between P-BK increment and the MBP reduction after captopril in EHT. ACEA, P-Ald, P-NE and plasma epinephrine showed no significant changes between responder and nonresponder groups. The present results suggest that bradykinin may be involved in the hypotensive action of captopril in the EHT sub-groups, where the renin angiotensin system appears to play an inert role for the elevation of blood pressure.

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