Testosterone and cortisol concentration in spermatic, adrenal and systemic venous blood in adult male guinea pigs.

Abstract

Testosterone (T) and cortisol (F) concentrations were measured in spermatic vein, adrenal vein and systemic blood of adult male guinea pigs before and after 4 days of treatment with ACTH, methylprednisolone acetate (MPA), or HCG. In the untreated animal, T concentrations were 1.0 Mg/100 ml in spermatic vein blood and 0.20 jug/100 ml in cardiac blood. Spermatic vein T concentration fell with ACTH, increased with HCG, and was unchanged by MPA treatment. The testosterone concentration in cardiac blood tended to be similar to adrenal venous blood levels and was always higher than in systemic blood obtained after organ blood collection. Normal F concentration was 488 /xg/100 ml in adrenal vein and 50 /ug/100 ml in cardiac blood. ACTH increased and MPA decreased all F levels. These results indicate that the testis is the main source of T secretion in the male guinea pig although the adrenal may secrete a biologically significant amount of gonadotropin suppressing steroid during pharmacological stimulation. There was no evidence of testicular F secretion. There was evidence that T production fell while F production was less labile during the period of organ blood collection. {Endocrinology 88: 523, 1971) T ARE few reports of testosterone (T) and cortisol (F) blood concentrations in the guinea pig. Even less is known about the level of these steroids during stimulation or suppression of the adrenal cortex or Leydig cells. Received August 21,1970. This investigation was supported by Grants TIAM-5350 and HD 72, through NIH. This study measured T and F concentrations in spermatic, adrenal and systemic blood of normal adult male guinea pigs, with and without hormone treatment. 1 Present adress: Department of Medicine, The Pennsylvania State University College of Medicine, The Milton S. Hershey Medical Center. Hershey, Pa. 17033. 524 NOTES AND COMMENTS Volume 88 TABLE 1. Blood testosterone concentrations (/xg/100 ml) from untreated guinea pigs and following four days of ACTH, MPAf, or HCG administration