Commercially available antisera against five subtypes of muscarinic receptors and nine subtypes of adrenoceptors showed highly distinct immunohistochemical staining patterns in rat ureter and stomach. However, using the M(1-4) muscarinic receptor subtypes and alpha(2B)-, beta(2)-, and beta(3)-adrenoceptors as examples, Western blots with membranes prepared from cell lines stably expressing various subtypes of muscarinic receptors or adrenoceptors revealed that each of the antisera recognized a set of proteins that differed between the cell lines used but lacked specificity for the claimed target receptor. We propose that receptor antibodies need better validation before they can reliably be used.
The ideal antiserum for immunohistochemical (IHC) applications contains mono-specific high-affinity antibodies with little nonspecific adherence to sections. Many commercially available antibodies are “affinity” purified, but it is unknown if they meet “hard” specificity criteria, such as absence of staining in tissues genetically deficient for the antigen or a staining pattern that is identical to that of an antibody raised against a different epitope on the same protein. Reviewers, therefore, often require additional characterization. Although the affinity-purified antibodies used in our study on the distribution of muscarinic receptors produced selective staining patterns on sections, few passed the preabsorption test, and none produced bands of the anticipated size on Western blots. More importantly, none showed a difference in staining pattern on sections or Western blots between wild-type and knockout mice. Because these antibodies were used in most studies published thus far, our findings cast doubts on the validity of the extant body of morphological knowledge of the whole family of muscarinic receptors. We formulate requirements that antibody-specification data sheets should meet and propose that journals for which IHC is a core technique facilitate consumer rating of antibodies. “Certified” antibodies could avoid fruitless and costly validation assays and should become the standard of commercial suppliers.
The function of the lower urinary tract is basically storage of urine in the bladder and the at-will periodic evacuation of the stored urine. Urinary incontinence is one of the most common lower urinary tract disorders in adults, but especially in the elderly female. The urethra, its sphincters, and the pelvic floor are key structures in the achievement of continence, but their basic anatomy is little known and, to some extent, still incompletely understood. Because questions with respect to continence arise from human morbidity, but are often investigated in rodent animal models, we present findings in human and rodent anatomy and histology. Differences between males and females in the role that the pelvic floor plays in the maintenance of continence are described. Furthermore, we briefly describe the embryologic origin of ureters, bladder, and urethra, because the developmental origin of structures such as the vesicoureteral junction, the bladder trigone, and the penile urethra are often invoked to explain (clinical) observations. As the human pelvic floor has acquired features in evolution that are typical for a species with bipedal movement, we also compare the pelvic floor of humans with that of rodents to better understand the rodent (or any other quadruped, for that matter) as an experimental model species. The general conclusion is that the "Bauplan" is well conserved, even though its common features are sometimes difficult to discern.
The study of the health status of the aging male takes presently a more integrative approach and it appears that ailments typical of male aging, such as lower urinary tract symptoms (LUTS), (visceral) obesity, metabolic syndrome and erectile failure are significantly interrelated. A common denominator of the above ailments is lower-than-normal testosterone levels occurring in a significant proportion of elderly men. This review addresses the potential connections between LUTS and late-onset hypogonadism. In animal studies there appear to be androgen and estrogen receptors in the urothelium and smooth muscle cells of the urethra and bladder of the rat and rabbit, as well as in the neurons in the autonomic ganglia of the prostatic plexus of the male rat. Upon castration electrically evoked relaxations of the smooth muscle of the prostatic urethra were decreased. There is a Rho-kinase activation/endothelin pathway; possibly involved in the increased smooth muscle activity found in both LUTS/benign prostate hyperplasia. Nitric oxide (NO) appears to have a smooth muscle relaxing effect in the urogenital organs. Studies in humans have convincingly shown that phosphodiestererase inhibitors have a beneficial effect on LUTS. More intervention studies should be undertaken to test the clinical validity of the theoretically plausible interrelationship between LUTS and late-onset hypogonadism.
The herbal extract Benja-ummarit (BU) is a traditional Thai medicine with a putative cancer-suppressing effect. However, this effect has only been tested in vitro in human hepatocarcinoma cell lines. The present study determined the efficacy of a BU extract to treat hepatocellular carcinoma (HCC) in rats in vivo and established its anti-angiogenic and anti-proliferative properties. The BU extract was prepared in 95% ethanol and its composition determined using liquid chromatography-mass spectrometry. HCC was induced in Wistar rats by an injection of diethylnitrosamine (DEN), followed 2 weeks later by injections of thioacetamide (TAA) thrice weekly for 4 weeks. Following 2 months, the DEN-TAA-treated rats were divided into 6 groups that were treated orally for another 2 months with: i) No treatment; ii) vehicle; iii) 30 mg/kg sorafenib (SF); iv) 1 mg/kg BU; v) 10 mg/kg BU; or vi) 50 mg/kg BU. Liver samples were collected for gross morphological, histological, reverse transcription-quantitative PCR and western blot analyses, and serum samples were collected for liver function tests. The size and number of the cancer nodules were reduced ~10-fold in BU-treated HCC groups and ~14-fold in the SF-treated group compared with the HCC group. Furthermore, the serum parameters of liver damage were lower in BU-compared with SF-treated rats. These results indicate that while each of these formulations strongly reduce HCC expansion, BU extract results in less liver damage. Vascular endothelial growth factor expression was reduced significantly in the BU-and SF-treated HCC groups compared with the HCC group (P<0.05). BU extract antagonizes HCC growth in vivo potently through inhibiting tumor angiogenesis. BU, therefore, qualifies as a promising medical herb requiring further evaluation as a treatment of HCC.
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