Perinatal development of gubernacular cones in rats and rabbits: Effect of exposure to anti‐androgens

Abstract

In male rats gubernacular cones develop during the latter half of prenatal life. Inversion of these papilla-like organs after birth is the first step to postnatal growth of the muscular cremaster sacs. The factors regulating prenatal growth and differentiation or postnatal inversion of these gubernacular cones are unknown. The lack of a detailed and unequivocal description of the normal gubernacular cone growth is judged at least partially responsible for this ignorance. The present study therefore describes the normal development of the gubernacular cones in male and female rats from day 14 of fetal life. Androgens are hypothesized to control male gubernacular cone development but recent evidence throws doubt upon this proposal. Therefore, the second part of this study describes perinatal development of gubernacular cones in male rat foetuses exposed to the anti-androgen flutamide from day 10 after conception. Quantitatively normal growth occurred prior to birth, indicating no role of androgen in this process. Excessive growth in length was noticed during the neonatal period together with delay of gubernacular cone inversion. These developmental alterations did not represent direct anti-androgen-induced modifications of gubernacular cones development as the alterations were not observed in flutamide-exposed neonatally castrated animals. Failure of androgens to affect directly perinatal gubernacular cone growth could represent a rat-specific feature. Fetal rabbits show the development of similar structures during the second half of fetal life.(ABSTRACT TRUNCATED AT 250 WORDS)

Hormonal Control of Gubernaculum Development during Testis Descent: Gubernaculum Outgrowth in Vitro Requires Both Insulin-Like Factor and Androgen**This work was supported by a grant from the Deutsche Forschungsgemeinschaft (through SFB 271, to I.M.A.).

“…On E17, the male gubernaculum in vivo was enlarged substantially compared with that in the female, which is in agreement with histological observations reported previ-ously (5,29,30). This difference can be explained by a difference in cell proliferation, as determined by BrdU labeling indexes.…”

Gubernacular cell division in different rodent models of cryptorchidism supports indirect androgenic action via the genitofemoral nerve

“…Using scanning electron microscopy, these studies showed inhibited downward growth of the processus vaginalis in 5-day-old flutamide-treated rats. Androgens influenced the growth of the processus vaginalis and gubernacular migration at the beginning of the second phase of testicular descent [20,30]. The present study shows that blockade of androgen suppresses DNA synthesis in the gubernacular tip during the time of maximal postnatal growth (day 2).…”

Human (and some other primates') uterine teres ligament represents a mammalian developmental novelty

“…Such a mass was noticed in the other species examined as well. In rats this structure contributes to the growth of the large (male) or small (female) inguinal cone and thus, in females, to the site of attachment of the inguinal fold of the uterine broad ligament (van der Schoot and Elger, 1993). In pigs this structure appeared the source of the temporarily observable but obvious intra-abdominal inguinal cone of young fetuses.…”