THAT the testes are related to the sexual characteristics of the individual and have
reproductive power was observed at an early time in history. One of the earliest descriptions …

THE ability of cells to interact and communicate is a biological phenomenon that developed
with the evolution of multicellular organisms. The cell-cell interactions that have evolved are …

II. Neurohormones/Neuropeptides A. GH-releasing hormone (GHRH) B. Pituitary adenylate
cyclase-activating peptide (PACAP)

BACKGROUND Leydig cells (LC) are the sites of testicular androgen production.
Development of LC occurs in the testes of most mammalian species as two distinct growth …

Adult Leydig cells originate within the testis postnatally. Their formation is a continuous
process involving gradual transformation of progenitors into the mature cell type. Despite the …

Interaction between growth and reproduction occurs in many vertebrates and is particularly
obvious at certain stages of the life cycle in fish. Endocrine interactions between the …

Leydig cells (LCs) are the cells of the testis that have as their primary function the production
of testosterone. LCs are a common target of compounds tested in rodent carcinogenicity …

The production of insulin-like growth factor I (IGF-I) and IGF-I binding protein (BP) was
investigated in Sertoli, Leydig and peritubular cells derived from the immature rat testis and …

Few data exist concerning the occurrence and potential role of an insulin‐like growth factor
(IGF) system in fish gonads. Using Northern and slot blot hybridization with a specific salmon …

Targeted gene deletion of insulin-like growth factor-I (IGF-I) results in diminished numbers of
Leydig cells (LCs) and lower circulating testosterone (T) levels in adult males. The impact of …