THE PHILIPPINE WATER BUFFALO

cells” had fewer zymogen granules and numeroud dilated
smooth endoplasmic reticulum. Pancreatic islets were very
few in number. A, B, C and D cells were identified. B cells
were the most predominant cell type. Their characteristic
feature was the presence of many pleomorphic granules.
Majority of the granules were round containing a
homogenous mass surrounded by a helo of variable size.
In some cells, there were numerous granules appearing
like dilated vacuole-like bodies containing pleomorphic
crystalloids bodies. The secretory granules of B cells
measured from 0.22µm-0.38µm. The secretory granules
of A cells were more uniform in shape than B cells and
consisted of dense homogenous core surrounded by a
tight membrane. They appeared to be uniformly distributed
around the nucleus. The granules measured about 0.13µm-
0.20µm. The secretory granules of D cells appeared
almost identical to those of A cells except that they were
fewer in number and less electron dense. They measured
approximately 0.16µm-0.22µm. C cells has scanty and
pale cytoplasm containing very few secretory granules.
Some C cells completely lacked secretory granules. X, F,
and E cells demonstrated in other species were not
observed in the Philippine water buffalo. The ultrastuctural
features of A, B, C and D cells of the pancreatic islets and
the pancreatic acinus of the Philippine water buffalo generally
conformed with those of other species of domestic animals.
Keywords: electron microscopic study, pancreatic acinus,
pancreatic islets, Philippine water buffalo
* The Philippine Journal of Veterinary Medicine, 41 (1): 1-
9, 2004.
A-37
GROSS AND MICROSCOPIC CHARACTERISTICS
OF THE SMALL AND LARGE LUTEAL CELLS OF
CORPUS LUTEUM OF PREGNANCY OF THE
PHILIPPINE WATER BUFFALO (Bubalus bubalis) *
C. P. Maala, Professor, College of Veterinary Medicine, University of the
Philippines Los Baños
M. T. S. Oñate, Assistant Professor, College of Veterinary Medicine,
University of the Philippines Los Baños
The corpus luteum of the Philippine water buffalo (Bubalus
bubalis L) during the early, middle, and late stages of
pregnancy was studied using hematoxylin and eosin
stained sections. Grossly, the corpus luteum appeared
pinkish red in color at the early stage of pregnancy and
was almost entirely embedded in the ovary, except for the
crown, which protruded into the ovarian stroma. During
middle and late stages of pregnancy, the corpus luteum
turned brownish in color and as pregnancy progressed, it
decreased in size. Microscopically, a well-developed
ANATOMY
connective tissue layer composed mainly of collagen fibers
surrounded the corpus luteum and divided it into lobules of
varying sizes. Large and small luteal cells made up the
cell population of the corpus luteum. The large cells were
polygonal in shape, with a large eccentric euchromatic
nucleus and eosinophilic cytoplasm. Cytoplasmic lipid
droplets were observed in large cells during the early
stages of pregnancy, which appeared to decrease in amount
in the middle and late stages of pregnancy. Eosinophilic
granules were visible in the cytoplasm of large cells in the
mid stage and were most numerous in the late stage of
pregnancy. Small cells were darker with a dense
heterochromic nucleus. Small cells and large cells were
largest during mid-pregnancy and early pregnancy,
respectively (P