Cheek pouch capacity in heteromyid rodents

Summary Diplacus aurantiacus produces a full canopy of leaves during the rainy winter and spring. As the drought begins in summer, all but the terminal leaves are lost. The leaves present during the growth period have a comparatively low specific weight and a high content of water, protein, and non-structural carbohydrate on a weight basis. Leaves of this type have a high carbon-gain per unit dry matter investment.The larvae of Euphydryas chalcedona utilize Diplacus as their principal food source. Following the first winter rains, the shrub starts to grow and the larvae of Euphydryas break diapause and begin actively feeding. Adults are produced which lay eggs that hatch into prediapause larvae. During the end of the growth period of the shrub, as the quality and quantity of Diplacus leaves decline, the prediapause larvae have a brief period of active feeding and growth and then enter diapause. Diplacus produces a leaf surface resin which inhibits the growth of Euphydryas larvae. It is present in the highest amounts on those few leaves that remain on the shrub during the drought period.The type and pattern of herbivore defense in Diplacus fits the model described for apparent plants.     

Histomorphology of the hamster cheek pouch

Histomorphology of the cheek pouch was studied in 14 hamsters by light and transmission electron microscopy. The cheek pouch wall was devoid of any lymphatic tissue and dense subepithelial tissue (i.e. the lamina propria) would render lymph drainage almost impossible and might constitute impermeable morphological barrier for non-recognition of transplants evoking a host immune response. Because in the literature it was reported that there is absence of any arteriovenous anastomoses on the pouch wall, and interruption of arterial supply failed to alter the growth rate of tissue grafts, we speculated that epidermal growth factors present in the saliva could play a role in maintaining the growth of tissue transplants.     

Rathke's pouch grafts in adult brain sites

Donor tissue containing Rathke's pouch (RP) with its associated mesenchyme and neural lobe was isolated from 15-day fetal rats and stereotaxically transplanted either to hypothalamic hypophysiotropic sites or to cerebral cortex of adult females for 30 days. Hosts either were intact or had been hypophysectomized 2-4 weeks prior to transplantation of Rathke's pouch. Grafts in the hypothalamus of either intact or hypophysectomized hosts were pleomorphic and large, often as wide as 1-2 mm, and occasionally larger. Grafts in the cortex of either intact or hypophysectomized hosts were nodular and occasionally projected upward in association with the meninges (cortex/meninges grafts). Certain features were characteristic of the grafts in all experimental groups, i.e., development of histotypic pars distalis with cell cords and fenestrated capillaries. In all experimental groups gonadotrophs and somatotrophs, when present, were localized at the graft margin adjacent to the connective-tissue interface; mammotrophs, when present, were distributed throughout the graft. Features specific to each experimental group also were apparent. Grafts in the hypothalamus of both intact and hypophysectomized hosts typically were encapsulated by a labyrinthine meshwork of cell processes, whereas cortex/meninges grafts directly abutted dense connective tissue or neural tissue. In hypothalamic grafts in intact hosts, moderately differentiated mammotrophs, gonadotrophs, and somatotrophs could be identified by their cytological features and immunopositivity for prolactin, luteinizing hormone, and growth hormone, respectively. In hypothalamic grafts in hypophysectomized hosts, mammotrophs were absent, and gonadotrophs and somatotrophs were poorly granulated and not abundant. Grafts in the cortex of intact hosts contained numerous, well-differentiated mammotrophs, gonadotrophs, and somatotrophs. Many of the mammotrophs in these grafts were hypertrophied, and profiles of exocytosis were common. In grafts in the cortex of hypophysectomized hosts, mammotrophs were either absent or very few, whereas gonadotrophs and somatotrophs were numerous. Gonadotrophs in these grafts were dramatically hypertrophied, although exocytosis was rare. The results indicate that development of histotypic pars distalis may occur in hypophysiotropic and non-hypophysiotropic brain sites and that the hormonal state of the host as well as implantation site modulate cytodifferentiation of specific pars distalis cell types.     

Polyester treatment in rats with a dorsal air pouch: chemotaxis in lavage fluid from the pouch]

Minced polyester threads introduced into peritoneal cavity of rats cause a granulomatous inflammation with evidence of macrophage stimulation. Chemotactic agents play an important role in the inflammatory reaction; they are released locally by cells involved in inflammation. In this paper the chemotactic effect of the peritoneal and subcutaneous air pouch fluids from rats bearing the polyester inflammatory process, have been studied on PMN cells "in vitro". The fluids were obtained by washing the cavity of untreated rats or rats injected with polyester, 7 days after the injection. The chemotactic response was assayed by employing modified chemotaxis Boyden chambers (Blind Well Neuro Probe) and polymorphonuclear cells from normal rats. Quantification of the migration was calculated by chemotactic index (A/B) (B = random migration, A = chemotaxis). The results demonstrate that a chemotactic activity is present in peritoneal and subcutaneous air pouch fluids following the inflammatory process. In conclusion the chronic inflammation determines the appearance of chemotactic factors for PMN cells, in the peritoneal cavity and in the air pouch, and the air pouch is a very convenient experimental system with the particular advantage that it permits easy repeated sampling of exudate during the course of an inflammatory response.     

Detached ciliary tufts in pouch of Douglas fluid

Detached ciliary tufts were observed in fluid obtained during laparoscopy from the pouch of Douglas of a young woman with secondary infertility. Previous reports of this finding are reviewed, and various etiologic factors in the production of these structures are discussed. This phenomenon appears to be a normal physiologic condition that results from exfoliation of the distal portion of the fallopian tube epithelial cells, possibly under the influence of progesterone in the luteal phase of the menstrual cycle.     

Guttural pouch mycosis by Emericella nidulans in a horse

A case of guttural pouch mycosis in a horse caused by Emericella nidulans is reported for the first time in Spain. The high incidence of E. nidulans in this special kind of mycoses is discussed.     

Experimental paracoccidioidomycosis of hamster inoculated in the cheek pouch

We compared the granuloma morphology and immune response of hamsters inoculated withParacoccidioides brasiliensis (Pb) into the cheek pouch, which lacks lymphatic drainage, and into the footpad, which is rich in lymphatics. Our objective was to better understand the modulation ofPb granuloma in an immunocompetent animal inoculated in an immunologically privileged site. The humoral immune response (ELISA) and cell mediated immunity (footpad test) became positive on days 7 and 14, respectively in animals inoculated into footpad and on days 35 and 60 in animals inoculated into the pouch. Typical epithelioid granulomas were observed at both sites on day 14. The number of fungi gradually decreased from the beginning of the experiment in footpad lesions, but only after day 35 in pouch granulomas, when cell mediated immunity was detectable. The results indicate that typical epithelioid paracoccidioidomycotic granulomas may develop in the absence of a detectable immune response; however, they are incapable of controlling fungal reproduction. Lack of lymphatic drainage delays the appearance of a detectable immune response, but with time fungi escape from the pouch, elicit an immune response and reach other organs. Our results further indicate the importance of the lymphatics in the pathogenesis of paracoccidioidomycosis.Abbreviations HCP hamster cheek pouch - Pb Paracoccidioides brasiliensis - Pbmycosis Paracoccidioidomycosis     

Aspiration cytology from the pouch of Douglas at hysteroscopy

Eighty-seven fine needle aspiration cytological samples from 29 patients suffering from irregular perimenopausal uterine bleeding were evaluated. Aspiration cytology was performed prior to hysteroscopy, after distension of the uterine cavity and finally after uterine curettage. In this paper, cytological examination of fluid from the pelvic content in women with benign endometrial findings is compared with that of patients with adenocarcinoma. Endometrial curettage influenced the cell content of the cytologica specimens.     

Free-radical inhibition of ATPase in hamster cheek pouch homogenates

The effects of free-radicals generated by either the oxidation of hypoxanthine by xanthine oxidase (HX/XO) or the lipoxidation of arachidonic acid (AA) on the ATPase of the hamster cheek pouch has been studied. Cheek pouches were removed from female golden syrian hamsters and homogenized. ATPase activity was measured by the production of Pi at 37 degrees. HX/XO and AA were added at a final concentration of 9.6 X 10(-5) M HX with 5 X 10(-2) units HX and 5 X 10(-5) M AA with and without 1 X 10(-4) M ouabain. HX/XO produced a 24.7% inhibition alone and 35.0% when combined with ouabain. Ouabain alone produced a 7.1% inhibition. AA produced a 23.6% inhibition alone and 24.3% inhibition when combined with ouabain. Ouabain alone produced a 5.4% inhibition in this series. When AA was added in doses ranging from 1 X 10(-5) to 2 X 10(-3) M, a plot of percent inhibition versus log dose followed a typical sigmoid type curve. The IC50 was 1.5 X 10(-4) M. These results suggest that free-radicals are capable of inhibiting the ATPase found in the hamster cheek pouch tissues. The possible modes of action of the free-radicals in producing this inhibition are discussed.     

Cheek pouch capacities and loading rates of heteromyid rodents

Rodents of the family Heteromyidae are proficient gatherers and hoarders of seeds. A major component of their adaptive specialization for harvesting and transporting seeds is their spacious, fur-lined cheek pouches. Precise measurements of cheek pouch capacities are essential if ecologists are to understand the foraging ecology, possible constraints on locomotion patterns, and competitive relationships of heteromyid rodents. To measure the size of these cheek pouches and the rate at which animals load seeds into their pouches during seed harvest, we attracted 56 individuals representing ten species of heteromyid rodents to bait stations in the field and allowed them to fill their cheek pouches with seeds several times while we observed and timed the events with the aid of night-vision equipment. The largest load taken by each individual was used as an estimate of its cheek pouch capacity. At the end of observations, each subject was captured and its mass and other data gathered. The allometric relationship between cheek pouch capacity and body mass for ten species of heteromyids was significant [pouch capacity (ml) = 0.148 body mass (g)^0.992, r ²=0.91, P<0.0001]. The regression coefficient is ≈1.0, which indicates that the volume of the cheek pouches scales in direct proportion to body size. When the data were subdivided into quadrupeds (Perognathus and Chaetodipus) and bipeds (Dipodomys) (n=5 for each), the relationships between pouch capacity and body mass were significant, but the two regressions were not significantly different from each other. When all loads (full and partial) were considered, subjects filled their cheek pouches an average of 93 ± 10% of pouch capacity (n=185). Cheek pouch capacities from published studies of artificially filled pouches of heteromyids in the laboratory averaged about 40% below the field measurements obtained here. The allometric relationship between mean loading rate and body mass was also significant [seeds/s=1.067 bodymass (g)^0.830, r ²=0.85,P=0.0011), but when quadrupeds and bipeds were considered separately, the relationships were not significant. Seed densities and bulk densities were used to calculate packing coefficients for seed species, which, when used in conjunction with the allometric relationship between cheek pouch capacity and body size, can be used to estimate the maximum load carried by a heteromyid. Except for the very largest kangaroo rat species, a full pouch load of Indian ricegrass seeds represents less than the daily energy requirements of an active heteromyid. Received: 3 March 1997 / Accepted: 15 July 1997