Age and Sex Differences in Weight of Pituitary Gland in Dogs

Abstract

Absolute and relative hypophysis weight is greater in the female than in thke male adult human( 1,2), rat(3,4) and pigeon(5). This difference does not exist before puberty in the human(6), rat(7), and rabbit(8). Indeed, Allanson( 9 ) found no sex difference in either immature or adult rabbits, while in the woodchuck( 10) the hypophysis is apparently larger in the male.The present investigation was undertaken in order to determine the hypophysis weightbody weight (HW/BW) ratios in immature, adult, an8d aged dogs.Methods. The dogs in which these ratios were determined had been used for acute studies in intestinal absorption. It was felt that these (experiments did not affect the h yp op h y si s .The dogs weighed from 3.71 to 35.5 kg (mean, 8.889 kg). Fifty-,two of the total of 91 dogs weighed from 5 to 9 kg. They were grouped by body weight in order to compare animals of similar size (TabZe I). While the exact age was not known, dogs whose teeth and genitalia indicated unmistakably that they were immature were classified as puppies.

Morphology and Ultrastructure of the Hypophysis in Bactrian Camels ( Camelus bactrianus )

“…The Bactrian camel had fully developed adenohypophysis that constituted 80 % of the volume of the hypophysis. It was worth noting that the pars intermedia was more developed than in humans and in most domestic animals (Hewitt, 1950;Dorst). We noticed an interesting phenomenon: some mammals that live in arid and semiarid areas had developed pars intermedia, like rodent and Bactrian camel, while undeveloped ones existed in humans, primates and domestic animals, or were even missing in elephants and whales.…”

Anatomical and histological characteristics of pituitary gland in domestic animals

“…It has a pale water-clear empty cytoplasm with dark spherical to ovoid nuclei (Malallahand Hussin 2010) (Figure 8). Rats, pigs, and camels have well-developed pars intermedia (Malallahand Hussin 2010;Hewitt 1950). It lies close to the neurohypophysis and is separated from the pars distalis by a cleft.…”