ABSTRACT
Americans profess a great love for their companion animals, and, indeed, their expenditures on food and other products for their dogs and cats would seem to confirm this. However, each year, many millions of dogs and cats are brought to animal shelters, where the majority are euthanized. Our inability to provide reasonably valid statistics related to this concern makes it difficult to offer a credible presentation on the need for a concerted effort to deal with the issue, design initiatives to ameliorate the problem, or evaluate progress and performance of these efforts. In this article we review some of the past efforts to document the scale of the "pet overpopulation" problem. We reexamine long-term shelter statistics from a single shelter system and present new data that reflect a recent cooperative effort to understand the origins and disposition of dogs and cats received by animal shelters.
ABSTRACT
Studies by Nelson (1971), Hirsch and McCauley (1977), and McGuire and Hirsch (1977) with the blow fly, Phormia regina, have reported evidence for conditioning. With respect to relative responsiveness to water or saline in the first position of the serial compound stimulus arrangement used, however, the evidence was inconsistent. These experiments show the effect on such responsiveness of the (a) method of mounting and (b) deprivation and satiation procedures. It is also possible that P. regina actively control internal ion concentration by saline intake.
Subject(s)
Conditioning, Classical/physiology , Diptera/physiology , Water-Electrolyte Balance , Animals , Sodium Chloride/administration & dosage , Water-Electrolyte Balance/drug effectsSubject(s)
Arousal , Conditioning, Classical , Diptera/genetics , Phenotype , Animals , Crosses, Genetic , Feeding Behavior , Hybridization, GeneticABSTRACT
The administration of the prostaglandin synthetase inhibitor indomethacin to the rat result in a significant increase of the number as well as the size and density of the lipid granules of renomedullary interstitial cells. The increased granularity is associated with the ultrastructural alterations of the organelles which are characteristic for cells with small secretory activity (a sparse rough and smooth endoplasmic reticulum and a small GOLGI complex). The findings indicate that there exists an inverse correlation between the number of the lipid granules of the interstitial cells and the secretory activity of these cells and seem to support the hypothesis that the interstitial cell lipid granules serve as storage site for renal prostaglandin precursors.
Subject(s)
Indomethacin/pharmacology , Kidney Medulla/ultrastructure , Animals , Cytoplasmic Granules/ultrastructure , Kidney Medulla/drug effects , Lipids/analysis , Male , Microscopy, Electron , Organoids/ultrastructure , Rats , Rats, Inbred StrainsABSTRACT
Under hypercalcemia induced by calcium gluconate the degranulation of renomedullary interstitial cells accompanied with the increase in volume of the rough and smooth surfaced endoplasmic reticulum and enlargement of the Golgi apparatus were observed. The ultrastructural changes can be regarded as an expression of the increase of a synthetic and secretory activity of these cells. Because the changes of renomedullary cells observed in hypercalcemia induced by calcium gluconate are not really different from that observed in hypercalcemia induced by vitamin D3 (Roszkiewicz et al. 1979) it can suppose that these changes may be connected solely with a calcium serum elevation and that the renomedullary interstitial cells rather do not play any important role in vitamin D3 metabolism.
Subject(s)
Hypercalcemia/chemically induced , Kidney Medulla/ultrastructure , Animals , Calcium Gluconate , Golgi Apparatus/ultrastructure , Hypercalcemia/pathology , Kidney Medulla/pathology , Male , Microscopy, Electron , RatsABSTRACT
Under short duration hypercalcemia induced by pharmacological doses of vitamin D3 significant ultrastructural changes were observed in the renomedullary interstitial cells of rats. The most striking alteration was the degranulation of these cells accompanied with the increase in volume of the rough and smooth-surfaced endoplasmic reticulum, enlargement of the Golgi apparatus and occurence of osmiophilic inclusions probably of lipid nature in mitochondria. The ultrastructural changes can be regarded as an expression of the increase of a synthetic and secretory activity of the renomedullary interstitial cells and they may be associated with an enhanced production of prostaglandins or other lipid hormonal substances than prostaglandins under condition of hypercalcemia.
