Laboratory of Animal Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kagawa, 761–0795, Japan
*Correspondence: Yoshiki Matsumoto, Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University 1750-1 Ikenobe, Miki-cho, Kagawa 761–0793, Japan, Tel: +81-87-891-2087, Fax: +81-87-891-2088, E-mail: myoshiki@med.kagawa-u.ac.jp
Transgenic Mini rat, in which the expression of intrinsic growth hormone (GH) gene is suppressed by the antisense GH transgene are characterized by definite somatic growth retardation at puberty. This study was carried out in order to evaluate age-related changes of hy-pothalamic somatostatin (SS) and pituitary luteinizing hormone (LH) in Mini rat. The anterior pituitary gland (AP) and hypothalamic periventricular nucleus (PeVN) were processed for immunohistochemistry with antisera to LH and SS, respectivery. LH-immunoreactive (IR) cells showed a decrease in number in Mini rat from 4 to 8 weeks of age, there was a significant increase in non-Mini rat. Interestingly, SS-IR cells in the PeVN showed the marked increase in number in Mini rat in contrast to the decrease in non-Mini rat during the same periods. The testis weights were not significantly different between Mini and non-Mini rat at 4 weeks of age, whereas at 6 and 8 weeks of age the value of Mini rat was significantly smaller than non-Mini rat. It is speculated that the onset and development of LH-testicular axis are recruited by pituitary GH secretion, which is responsible for SS secretion.
Periventricular hypothalamic nucleus, Somatostatin, Luteinizing hormone, Growth hormone, Pituitary gland, Mini rat
