Testis of Prepubertal Rhesus Monkeys Receives a Dual Catecholaminergic Input Provided by the Extrinsic Innervation and an Intragonadal Source of Catecholamines1
| Autor: | Lonnie D. Russell, K.-Y. F. Pau, Sergio R. Ojeda, Hernan E. Lara, Artur Mayerhofer, Michael V. Danilchik |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Catecholaminergic
medicine.medical_specialty education.field_of_study Tyrosine hydroxylase Adrenal gland Population Ovary Cell Biology General Medicine Testicle Biology chemistry.chemical_compound medicine.anatomical_structure Endocrinology Reproductive Medicine chemistry Internal medicine medicine Catecholamine Neurotransmitter education medicine.drug |
| Zdroj: | Biology of Reproduction. 55:509-518 |
| ISSN: | 1529-7268 0006-3363 |
| DOI: | 10.1095/biolreprod55.3.509 |
| Popis: | The mammalian testis is innervated by extrinsic catecholaminergic nerves and responds to catecholamines with steroid secretion. Although the primate testis has also been shown to be innervated, potential differences in the density of this innervation between immature and sexually developed individuals have not been described. A recent study demonstrated that the primate ovary contains a network of neuron-like cells and that some of these cells are catecholaminergic. It is thus possible that the male gonad is also endowed with a similar intragonadal source of catecholamines. The present study addresses these two issues. Catecholaminergic nerves were identified as such by their content of immunoreactive tyrosine hydroxylase (TH; the rate-limiting step in catecholamine biosynthesis), and in some cases by glyoxylic acid histochemistry. Fibers containing TH were abundant in testes from juvenile animals (1-2 yr of postnatal life), but the density of this innervation was not maintained in adult animals, whose testis showed only a few TH-positive fibers scattered in the interstitial tissue. Testicular norepinephrine (NE) concentration was much lower in adult than in juvenile animals, suggesting that the marked increase in testicular weight that occurs with the attainment of sexual maturity is not accompanied by corresponding changes in NE content. At the ultrastructural level, testicular nerve fibers contained pleiomorphic, dense-core and clear vesicles, suggesting the presence of catecholamines and other neurotransmitters. In addition to this extrinsic catecholaminergic innervation, prepubertal testes, but not adult gonads, contained an intrinsic population of TH-immunopositive neuron-like elements, identified as cells by confocal scanning laser microscopy. To determine whether the prepubertal monkey testis indeed expresses the TH gene, testicular RNA was subjected to reverse transcriptase polymerase chain reaction to amplify the 5' end of TH mRNA, which encodes the regulatory domain of the enzyme. The cDNA that was obtained predicts an amino acid sequence similar, but not identical, to that encoded by the alternatively spliced type 1 TH mRNA form present in the adrenal gland. These results indicate |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|