The low rate of filtration and lymph formation in most tissues can be explained by standing plasma protein gradients within the intercellular cleft of continuous capillaries (glycocalyx model) and around fenestrations. kidney, intestinal mucosa), fluid absorption is sustained by local epithelial secretions, which flush interstitial plasma proteins into the lymphatic system. This is due in part to the inverse relation between filtration rate and ISF plasma protein concentration ISF colloid osmotic pressure (COP) rises as J(v) falls. Sum-of-forces evidence and direct observations show that microvascular absorption is transient in most tissues slight filtration prevails in the steady state, even in venules. The traditional form of Starling's principle has to be modified in light of insights into the role of ISF pressures and the recognition of the glycocalyx as the semipermeable layer of endothelium. Microvascular fluid exchange (flow J(v)) underlies plasma/interstitial fluid (ISF) balance and oedematous swelling. Outcomes of such studies might ultimately be useful in predicting and improving in vivo PK performance of IM injected drugs. Taking cues from existing in vitro modelling technologies, the purpose of this article is to propose “critical parameters” of the IM environment that could be examined in hypothesis-driven studies. vaccine administration, however immune responses post-injection are not in the scope of this article.
![electrolyte composition of body fluid compartments electrolyte composition of body fluid compartments](http://image.slidesharecdn.com/lect4-electrolytesbalance-110716031722-phpapp02/95/lect-4-electrolytes-balance-7-728.jpg)
Immune responses occur by design after e.g. Interplay between the typically non-physiological aspects of drug formulations and the homeostatic IM environment may provide insights into the fate of drugs at the IM injection site, leading to predictions of how a drug will behave post-injection in vivo. An improved understanding of injection site events could improve approaches taken by formulation scientists to identify therapeutically effective and consistent drug PK outcomes. While the wide range of commercial IM pharmaceuticals provide a wealth of pharmacokinetic (PK) information following injection, there remains an inadequate understanding of drug fate at the IM injection site that could dictate these PK outcomes. Intramuscular (IM) injections are a well-established method of delivering a variety of therapeutics formulated for parenteral administration. These results demonstrate that multiple factors need to be considered when determining the best way to compare fluid intake between males and females and provides insight to help explain the discrepancies in the literature regarding sex differences in fluid intake. This effect, however, is likely the result of a relationship between body weight and food intake because when food was absent or reduced, the correlation between body weight and intake disappeared. Finally, we report that daily water intake correlated with body weight in females. We found no relationship between intake and body weight after water deprivation, furosemide treatment, or isoproterenol treatment in females, nor did we find a relationship between intake and body weight after hypertonic saline treatment in either males or females.
![electrolyte composition of body fluid compartments electrolyte composition of body fluid compartments](https://www.austincc.edu/apreview/NursingPics/FluidPics/Picture2.jpg)
We found that intake stimulated by either water deprivation or furosemide correlated with body weight in male rats. Here we investigated whether body weight correlated with fluid intake stimulated by additional dipsogenic agents in male and female rats. Only after a pharmacological dose of AngII did water intake correlate with body weight, and only in males. We, however, previously demonstrated sex differences in the relationship between body weight and angiotensin II (AngII)-stimulated water intake.
![electrolyte composition of body fluid compartments electrolyte composition of body fluid compartments](http://image.slidesharecdn.com/physio-120111100416-phpapp02/95/body-fluids-and-edema-by-dr-irum-4-728.jpg)
Nonuniform application of this body weight correction likely contributes to discrepancies in the literature.
![electrolyte composition of body fluid compartments electrolyte composition of body fluid compartments](https://biocyclopedia.com/index/general_zoology/images/images36/fig001.jpg)
The assumption that body weight is a predictor of fluid intake is often used as rationale for normalizing intake to body weight when examining sex differences in drinking behavior.