Ontogeny of the expression of some catecholamine synthesising enzymes in the female porcine preoptic area.
Ontogeny of the catecholaminergic system of the preoptic area (PA) was studied in various animal species including mice, rats, cats and lower vertebrates. Until now, there has been no data about development of catecholaminergic structures in the porcine PA. To study this problem, hypothalami from six groups of animals were collected. Three groups of foetuses (70, 84 and 112 days old) and three groups of female pigs (1 day, 10 weeks and 7-8 months old) were used. Nerve structures immunoreactive for the studied substances: tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH) and phenylethanoloamine-N-metylthransferase (PNMT) were observed in different periods. In PA, TH-IR (immunoreactive) structures appeared before 70th day of foetal life, DbetaH-IR between 70th and 84th day of foetal live and PNMT-IR only in 10-week old and adult animals. In the PA of 70-day old foetuses, single smooth and varicose nerve fibres immunoreactive only to TH were found. In PA of 84-day old foetuses, additionally, single nerve cell bodies immunoreactive to TH were shown and some of them also contained immunoreactivity to DbetaH. In PA of 1-day old piglets, moderate numbers of nerve fibres immunoreactive to TH and only single TH/DbetaH-IR nerve terminals were observed. TH-IR nerve cell bodies were also moderate in number and many of them contained simultaneously immunoreactivity to DbetaH. In PA of 10-week old pigs, a moderate number of immunopositive nerve fibres was observed. They contained mainly TH, but part of them stained also for TH/DbetaH. Only very few nerve fibres containing exclusively DbetaH were found. These nerve terminals were observed in a close vicinity of blood vessels. In PA, moderate numbers of TH-IR nerve cell bodies were found, some of them contained also immunoreactivity to DH but never to PNMT. Perikarya containing PNMT were TH-negative. In the PA of sexually mature sows, additional, single, large nerve cell bodies (about 35 microm in a diameter) containing TH only were found. In many cases, TH- and DbetaH-IR "basket-like" structures surrounding nerve cell bodies were seen, suggesting an influence of those fibres on the neuronal activity.
Sienkiewicz
Waldemar
W
Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland. sienio@moskit.uwm.edu.pl
D000818:Animals; D002395:Catecholamines / Q000096:biosynthesis*; D002452:Cell Count; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D005260:Female; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D009412:Nerve Fibers / Q000473:pathology / Q000648:ultrastructure; D010625:Phenylethanolamine N-Methyltransferase / Q000378:metabolism; D011247:Pregnancy; D011301:Preoptic Area / Q000201:enzymology* / Q000254:growth & development*; D012741:Sexual Maturation / Q000502:physiology; D013552:Swine; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D002395:Catecholamines; D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase; D010625:Phenylethanolamine N-Methyltransferase