Androgenic control of the cyclic AMP-dependent protein kinase isoenzymes of the rat epididymis

Abstract

Summary. The specific activity of the type I and type II isoenzyme forms of the cAMP-dependent protein kinase (EC 2.7.1.37) in the caput epididymidis of the intact rat was less than that of the caudal region while the isoenzyme ratio (type II :type I) of the former was greater than that of the latter, with type II being the predominant form in both regions. By 7 days after castration, the specific activities in both regions had decreased to the same level. The isoenzyme ratio of the caudal region increased to that of the caput region which remained unchanged after castration. The change in the isoenzyme ratio in the caudal region was mainly due to loss of the type I isoenzyme. The castration effects were reversed by testosterone administration.

Phosphorylated secretory proteins from rat epididymis and their androgenic control

“…[ -32 ] would be used by protein kinases to form radioactive phosphorylated proteins. After the incubation, the tissue slices were separated from the medium, washed and the cytosolic fraction was prepared as described previously (Mongkolsirikieat & Chulavatnatol, 1983). Using 2-dimensional gel electrophoresis and autoradiography, the cytosolic fraction yielded a very complex pattern consisting of numerous radioactive proteins while the medium showed a simple pattern of fewer radioactive proteins.…”

“…Androgen withdrawal is known to prevent the synthesis of epididymal secretory proteins (Brooks, 1981b) and to decrease the activity and to change the isoenzymes of protein kinase (Mongkolsirikieat & Chulavatnatol, 1983). Both processes may contribute to the observed decrease in the phosphorylated secretory proteins from the androgen-deficient rats.…”

“…After adding the ice-cold HBSS and pelleting the tissue slices by centrifugation, the collected tissue slices were resuspended in HBSS and washed twice by centrifuging through a layer of 3% Ficoll as described by Mongkolsirikieat & Chulavatnatol (1983). The washed tissue slices were re-incubated in 300 pi HBSS alone at 33°C for 3 h (chase period).…”

Busulfan administration replicated the characteristics of the epididymal initial segment observed in mice lacking testis-epididymis lumicrine signaling

“…Previous studies have shown that many genes are expressed in the epididymis and are regulated by testicular endocrine and/or lumicrine signaling [ 6 , 13 , 16 , 24 , 31 , 34 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 ,…”