Abstract
The expression of the bovine growth hormone receptor (GHR) was detected in various tissues by a reverse transcription-polymerase chain reaction system (RT-PCR). For the quantifica-tion of the bovine 438 bp GHR cDNA fragments a HPLC-UV detection system was used. bGHR amplificates were well detectable in liver from cows, heifers and in fetal liver. bGHR expression was also demonstrated in mammary gland, kidney and in adipose tissue. Lower but significant amounts of bGHR amplificates were obtained in skeletal muscle and in rumen villi, indicating a potential new mode of action of GH via affecting the gastrointestinal tract. bGHR mRNA was detected in various female and male reproductive tissues, i.e. in uterus, oviduct, corpus luteum, and in the vesicular gland. No bGHR expression was detectable in testes from adult bulls. A long-term treatment of heifers with a slow-release preparation of bovine growth hormone had no effect on either bGHR-mRNA expression in liver or on GH binding capacity on liver membrane prepara-tions. These results demonstrate that the RT-PCR system together with a HPLC-UV detection system provides a useful strategy to study GHR expression and regulation in different tissues under various conditions.
