Essential hypertension has been regarded to have a common feature of non-insulin-dependent diabetes mellitus (NIDDM) or obesity, i. e. insulin resistance. Although candidate genes have been listed, an exact mechanism (s) has not been identified. A diminished skeletal muscle blood flow may be one of mechanisms of inslin resitance. It is very important to select antihypertensive agents such as α₁-blodker or ACE inhibitors to dilate vasculature and hence improve insulin resistance. Insulin sensitizer such as troglitazone, which will be shortly on the market, may be another choice to not only NIDDM and/or obesity but also essential hypertensives with insulin resistance.

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Estrogen production within the prostate gland has been a subject of considerable controversy for many years. We showed that estradiol concentration was 31.9, 63.2 and 25.1 pg/g in rat, dog and human prostate, respectively. We demonstrated estrogen formation from androst-4-ene-3, 17-dione in human, dog and rat prostate. (1) The kinetics of the aromatase of rat and dog prostate was measured using the ³H₂O-release assay. Aromatase activity increased with respect to incubation time, prostate tissue amount and substrate concentration. 4-hydroxyandrostenedione (4-OH-A) inhibited aromatization by 64-87% and 47-93% in rat and dog prostate, respectively. K_m and V_max values in rat prostate were 18.2nM and 16.2fmol estrogen/mg protein/hr compared to 7.6nM and 4.9fmol estrogen/mg protein/hr in dog prostate. The conversion rate from androstenedione to estrogen was 2.1% in rat prostate. (2) Estrogen production was determined in human and rat prostate using estrogen formation assay. The retention time of the estradiol 3-methyl ether fraction that was reduced and methylated from the estrone-containing fraction derivative was the same as that of natural estradiol 3-methyl ether. This fraction was recrystallized to achieve a constant specific activity. In human BPH tissue and rat prostate, production of estrone from androstenedione could be detected and conversion rates were 0.09% and 0.05%, respectively.
We conclude that aromatization of androgen exists in human, dog and rat prostate, and localized estrogen synthesis by the aromatase enzyme is an important aspect of steroid hormone action in the etiology of BPH.

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Cardiovascular accidents are major causes of death in acromegaly because of its frequent association with multiple cardiovascular risk factors such as diabetes, hypertension and dyslipidemia. Elevated serum lipoprotein (a) (Lp (a)) level is another independent risk factor. However, little is known about the contribution of Lp (a) to cardiovascular disorders in acromegaly. We determined the serum concentrations of Lp (a) in acromegalic patients before and after pituitary adenomectomy. In pre-operative 12 patients, serum Lp (a) levels were significantly higher compared with 32 healthy volunteers (27.5±4.3 mg/dl vs. 14.5±1.8 mg/dl, p<0.005). After operation, serum GH levels markedly decreased from 24.0±6.7 ng/ml to 3.9±1.1ng/ml (p<0.02), and serum Lp (a) levels slightly (although not significantly) decreased from 27.7±7.4 mg/dl to 14.0±4.0 mg/dl (p=0.067). Serum triglyceride levels decreased from 155±33 mg/dl to 81±11 mg/dl (p<0.05), and serum HDL-cholesterol levels increased from 37±6 mg/dl to 59±7 mg/dl (p<0.05). Serum total cholesterol levels were unaffected by operation (173±17 mg/dl vs. 180±13 mg/dl). Our data suggest that GH may be involved in the regulation of serum Lp (a) levels, and that in untreated acromegalic patients, elevated Lp (a) levels might accelerate the development of atherosclerosis in concert with other cardiovascular risk factors.

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To investigate iodine metabolism in postpartum hypothyroidism and to confirm security of lactation, we examined serum nonhormonal iodine (SNI) and iodine in milk in 10 patients who have experienced transient hypothyroidism 4-7 months after delivery. Age-matched 26 postpartum normal subjects were selected as control. In hypothyroid cases 7 out of 10 had large goiter (III degree) and 9 out of 10 cases possessed high titer of MCHA (?80²). High levels of SNI and serum Tg were found in 20% and in 60%, respectively. Whilst iodine contents in milk were high immediately after delivery and decreased gradually during 6 months thereafter in 6 control subjects, those in hypothyroid cases increased remarkably at onset and were significantly high compared with controls. Iodine contents in milk in 80% of hypothyroid cases were more than M+2SD (25.5 μg/dl) of those in controls. Elevated iodine in milk declined within normal limit after 1-2 months. Postpartum hypothyroid patients were divided into 3 stages; first latent hypothyroid stage which was one week after delivery, second overt hypothyroid stage that was 1-2 months after delivery and third euthyroid stage thereafter. Differences of iodine in milk among 3 stages in hypothyroidism were significant (H=13.2, p<0.01). Iodine contents in milk were significantly correlated with serum Tg levels in hypothyroid cases (r_s=+0.82, p<0.01) and those in subjects with large goiter tend to be higher than those with small goiter. It was considered that iodine distribution space in whole body may be enlarged in postpartum hypothyroidism and iodine may be markedly excreted out of body through milk as well as urine.
These results suggest that iodine content in milk could be an indicator for the degree of thyroid follicular destruction and breast milk in postpartum hypothyroidism may be harmless to the neonatal thyroid gland.

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