Changes in rat testicular adenylate cyclase activities and gonadotrophin binding during unilateral experimental cryptorchidism

Abstract

Unilaterally cryptorchid rats were examined at 3, 8, 15, 22 and 28 days after operation. There was a selective decrease in the adenylate cyclase (ATP pyrophosphate--lyase (cyclizing), EC 4.6.1.1) responses to gonadotrophin stimulation in the abdominal testis. This was associated with a parallel decrease in specific FSH and LH binding. There was no reduction in the response of testicular adenylate cyclases to prostaglandin (PG) E-1 or fluoride stimulation, indicating that both the GTP binding protein (N-component) and the catalytic subunit of the adenylate cyclase complexes were intact. The reduction in FSH-responsive adenylate cyclase activity in the abdominal testis was not due to a change in the Km for adenylate cyclase activation, but was due to a reduction in maximal velocities. Unilateral cryptorchidism was also associated with a rapid decline in soluble Mn2+-dependent adenylate cyclase activity in germ cells (spermatids). By 3 days after operation there was an 82% decrease in germ cell adenylate cyclase activity. The loss of soluble Mn2+-dependent adenylate cyclase activity was associated with a parallel decrease in Sertoli cell secretion of androgen binding protein, indicating that Sertoli cell factors may be important for the maintenance of germ cell adenylate cyclase activity. The desensitization of the gonadotrophin--responsive adenylate cyclases and the loss of gonadotrophin receptors in Leydig and Sertoli cells were not due to changes in plasma gonadotrophin values because LH concentrations were within normal limits and plasma FSH was only marginally elevated in the cryptorchid rats. No significant alterations of any of these parameters were seen in the scrotal testis of unilaterally cryptorchid rats when compared to values for intact controls.

Changes in germ cell adenylate cyclase and protein carboxyl methylase activities in rat testicular tissue during bilateral cryptorchidism and after orchidopexy

“…Soluble 2 +-dependent adenylate cyclase is localized in haploid germ cells (Braun & Dods, 1975;Cusan, Gordeladze, Parvinen, Clausen & Hansson, 1981b;Gordeladze, Purvis, Clausen, Rommerts & Hansson, 1981). We have previously shown that the activity of this enzyme is reduced by 82% within 3 days of experimental cryptorchidism in adult rats (Jahnsen et al, 1981). Protein carboxyl methylase is another enzyme that is preferentially localized in haploid germ cells (Gagnon, Axelrod, M usto, Dym & Bardin, 1979), and testis-specific isoenzymes have been described (Cusan, Gordeladze, Andersen & Hansson, 1981a).…”

“…Germ cells, Sertoli cells and Leydig cells have all been shown to be functionally damaged during cryptorchidism (Hagenäs & Ritzen, 1976;Hagenäs, Ritzen, Svensson, Hansson & Purvis, 1978; Kretser, Sharpe & Swanston, 1979; Kerr, Rieh & de Jahnsen, Gordeladze, Haug & Hansson, 1981). Soluble 2 +-dependent adenylate cyclase is localized in haploid germ cells (Braun & Dods, 1975;Cusan, Gordeladze, Parvinen, Clausen & Hansson, 1981b;Gordeladze, Purvis, Clausen, Rommerts & Hansson, 1981).…”

Changes in isoproterenol-stimulated adenylate cyclase activity in rat testicular tissue during cryptorchidism and after orchidopexy

“…In addition, rat Leydig cells probably also possess ß-adrenergic receptors since isoproterenol activates adenylate cyclase activity in rat tumour Leydig cells (T. Jahnsen, unpublished data). Jahnsen, Gordeladze, Haug & Hansson (1981) In Exp. II, 72 male Sprague-Dawley rats (6/group) were used at 17 days of age : rats in 4 groups were subjected to sham-operations, rats in 7 groups were made bilaterally cryptorchid and those in the final group were killed at the beginning of the experiment.…”

“…At 42, 59 and 120 days of age, one group each of control, cryptorchid and surgically treated animals was killed. Surgical techniques and treatment of the animals were as described previously (Jahnsen et al, 1981 ;Karpe et al, 1981) (Salomon, Londos & Rodbell, 1974), with the modifications described by Birnbaumer, Yang, Hunzicker-Dunn, Bockaert & Duran (1976).…”