Vol. 10, No 3, 2003 pp. 120 - 126
UC 619:[636.1:636.454
SEASONALITY, FOLLICULOGENESIS AND LUTEOGENESIS
IN MARE OVARIES
Danica Marković1, Miloš Pavlović2,
Vojislav Pavlović3
1 Department of Histology and Embriology,
Faculty of Veterinary Medicine, University of Belgrade
e-mail: danicams@EUnet.yu
2 Ministry of Agriculture of the Republic
Serbia, Belgrade,
3 Department of Obstetrics and Gynaecology,
Faculty of Veterinary Medicine, University of Belgrade,
Serbia and Montenegro
Summary. In the horse the circannual rhythm of reproduction is cued
primarily by photoperiod changes. This environmental signal is translated
to an endocrine signal in the habenulo- pineal gland. In the mare, short
daylenght is associated with a decrease in gonadotropin secretion and consequently
a decrease in ovarian activity. The ovary of the mare is unique in its
structure and different from other mammals. Ovaries were cut around the
fossa ovulations, and analyzed during the seasonal period of mare (10)
estrus cycle (March-July). Tissue sections were fixed in Bouien fixative,
and then HE stained. The relationship of localization of cortex., medulla
and fossa ovulations is investigated. The ovulation fossa is localized
in the center of the ovary and is surrounded by broad ovarian cortex. Medulla
is localized in a narrow peripheral area. The cortex area ahead of the
fossa is occupied by developing follicles. Variously sized follicles were
identified and ovocyte-cumulus connections will be considered. The inside
cavity from the evacuated follicle, fills rapidly with blood forming Corpus
Hemorrhagicum followed by creation of lutel tissue. Corpus Luteum in mare
is the largest comparing the other animals, pear-triangle shaped, size
0.5-1 cm, covered by dense tunica albuginea, inside the fossa.
The regulatory mechanisms of seasonality are on the strong influence
and connection between hypothalamo-pituitary-gonadal axis and we discuss
the implications with regard to investigation strategies to advanced the
onset of cyclic reproductive activity in the early spring.
Key words: Seasonality, ovary, mare, reproduction, folliculogenesis,
luteogenesis
SEZONALNOST, FOLIKULOGENEZA I LUTEOGENEZA
U JAJNICIMA KOBILE
Kratak sadržaj: Godišnji ciklus parenja konja je u značajnoj zavisnosti
od fotoperiodičnih promena. Ovakvi podsticaji iz okoline bivaju prevedeni
u endokrine signale u habenulo- pinealnoj žlezdi. Kod kobile, kratko trajanje
dnevne svetlosti je povezano sa opadanjem lučenja gonadotropina što dovodi
do posledičnog opadanja aktivnosti jajnika. Jajnik kobile je jedinstvene
strukture i razlikuje se od jajnika ostalih sisara. Jajnici su sečeni u
oblasti fose ovulationis, i potom analizirani u sezoni parenja kod kobila
(10), tokom estrusnog ciklusa (mart-juli). Tkivni isečci su fiksirani u
Bujen fiksativima, a zatim bojeni Hematoksilin-eozinom. Posmatrani su odnosi
i relacije rasporeda kore, srži i fose ovulationes. Ovulatorna fosa je
lokalizovana u centru jajnika i okružena gustim ovarijalnim korteksom.
Srž je razmeštena u uskoj zoni na periferiji. Područje kore koja okružuje
fosu ispunjeno je folikulima u razvoju. Posmatrani su folikuli različitih
veličina i utvrđivani su odnosi ovocita i okolnih ćelija. Unutrašnja šupljina
oslobođenog folikula brzo se ispunjava krvlju obrazujući hemoragično telo
od koga će se formirati lutealno tkivo. Kobila ima najveće žuto telo u
poređenju sa drugim životinjama. Ono je kruškoliko- trouglastog oblika,
veličine oko 0,5-1 cm, i obavijeno gustom tunikom albugineom, smešteno
u unutrašnjosti fose.
Mehanizmi regulacije sezonalnosti su pod snažnim uticajem i povezanosti
između hipotalamo- pituitarno- gonadalne sprege i mi smo razmatrali rezultate
imajući u vidu početak ciklusa reproduktivnih aktivnosti u toku ranog proleća.
Ključne reči: sezonalnost, ovarium, kobila, reprodukcija, folikulogeneza,
luteogeneza
