Distribution of substance P-like immunoreactivity in the central nervous system of the rat—I. Cell bodies and nerve terminals

On the specificity of naloxone as an opiate antagonist.

For years, it has been held that cathepsin D (CD) is involved in rather non-specific protein degradation in a strongly acidic milieu of lysosomes. Studies with CD knock-out mice revealed that CD is not necessary for embryonal development, but it is indispensable for postnatal tissue homeostasis. Mutation that abolishes CD enzymatic activity causes neuronal ceroid lipofuscinosis (NCL) characterized by severe neurodegeneration, developmental regression, visual loss and epilepsy in both animals and humans. In the last decade, however, an increasing number of studies demonstrated that enzymatic function of CD is not restricted solely to acidic milieu of lysosomes with important consequences in regulation of apoptosis. In addition to CD enzymatic activity, it has been shown that apoptosis is also regulated by catalytically inactive mutants of CD which suggests that CD interacts with other important molecules and influences cell signaling. Moreover, procathepsin D (pCD), secreted from cancer cells, acts as a mitogen on both cancer and stromal cells and stimulates their pro-invasive and pro-metastatic properties. Numerous studies found that pCD/CD level represents an independent prognostic factor in a variety of cancers and is therefore considered to be a potential target of anti-cancer therapy. Studies dealing with functions of cathepsin D are complicated by the fact that there are several simultaneous forms of CD in a cell—pCD, intermediate enzymatically active CD and mature heavy and light chain CD. It became evident that these forms may differently regulate the above-mentioned processes. In this article, we review the possible functions of CD and its various forms in cells and organisms during physiological and pathological conditions.

Cathepsin D--many functions of one aspartic protease.

Opiates are among the oldest pharmacological substances known to man; their analgesic, euphoric, and addictive effects have been traditional focal points for opiate research. Without doubt, the cardiovascular effects of opiates have also been apparent to the user or abuser of opiate substances for several centuries. Persons seeking analgesic, euphoric, or antidiarrheal actions from opiate alkaloids have probably noted dizziness upon sudden st,anding due to the orthostatic hypotension these substances produce. His­ torically, however, scientific study on the cardiovascular responses to ad­ ministered opiates has lagged behind other areas of opiate research. This is understandable as, relative to doses required for their analgesic actions in humans, the cardiovascular effects of opiates are less noticeable and, indeed, undesirable. Early studies established that cardiovascular responses to morphine var­ ied among species; both autonomic and histamine-releasing properties con­ tributed to their hypotensive and bradycardic actions (1-5). Generally speaking, morphine was shown to produce prominent effects upon brain­ stem and hypothalamic centers that resulted in increased parasympathetic and decreased sympathetic tone (3-6). These effects upon autonomic out­ flow caused a depression of both heart rate and blood pressure. A resurgence of interest in opiate-cardiovascular interactions followed the discovery of endogenous opiate systems (for review see 7). A family of opioid peptides were found to be located at sites suggesting an autonomic action (8); also, opiate receptors were shown to be densely distributed in the brainstem and hypothalamus in close proximity to cardiovascular centers as well as endogenous opiate pathways (9, to). These anatomical findings

Cardiovascular Effects of Endogenous Opiate Systems

Introduction ON JUNE 24, 1971, Andrew V. Schally announced the determination of the primary structure of porcine GnRH at The Endocrine Society Meeting in San Francisco. This announcement was followed by publications by Matsuo et al. (1, 2) and Baba et al. (3) on the proposed amino acid sequence for porcine GnRH and its synthesis and by Burgus et al. (4) who characterized ovine GnRH and found the sequence to be identical with that of porcine GnRH. The physiological and therapeutic importance attributed to the discovery of the new substance was greatly increased by the prospect of the design of potent and long acting GnRH agonists and antagonists. Since that time more than 2000 analogs of GnRH have been synthesized. The impact of research of GnRH and its analogs on clinical medicine recently led Ziporyn (5) to note, “There's almost no subspecialty of medicine that will be left untouched by the [research] advances associated with LHRH or its analogs.” It is the intent of this article to provide a historical ...

Gonadotropin-releasing hormone analog design. Structure-function studies toward the development of agonists and antagonists: rationale and perspective.

Enzymatic inactivation of substance P by a partially purified enzyme from rat brain.

Co-identity of brain angiotensin converting enzyme with a membrane bound dipeptidyl carboxypeptidase inactivating Met - enkephalin.

Differences in the degradation of hypothalamic releasing factors by rat and human serum.

Myelin basic protein, purified from bovine spinal cord, is cleaved by a purified bovine brain acid proteinase to yield three peptide fragments which were purified by gel filtration procedures combined with preparative gel electrophoresis. The purity of the fragments was established by end group analysis, amino acid analysis, polyacrylamide disc gel electrophoresis, and by their encephalitogenic activity. Chemical and biological characterization shows that one peptide, (peptide II), originates from the N-terminal end of the basic protein and contains residues 1–43; a second peptide, (peptide I), contains residues 44–89 and a third peptide (peptide III). originates from the C-terminal region with an N-terminal phenylalanine, residue 90, through arginine, residue 170, of the basic protein. The combined amino acid composition of the three fragments account for the amino acid content of the basic protein. The structure of the three peptides demonstrates that the purified brain acid proteinase selectively cleaves the two phenylalanine-phenylalanine linkages formed between residues 43–44 and 89–90 of the basic protein molecule. This study shows that cathepsin D could be the endogenous enzyme responsible for the breakdown of basic protein to form smaller encephalitogenic fragments, some of which are known to be present in crude tissue extracts.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1975.tb04033.x

Myron Benuck

Papers

Enzymatic inactivation of substance P by a partially purified enzyme from rat brain.

Co-identity of brain angiotensin converting enzyme with a membrane bound dipeptidyl carboxypeptidase inactivating Met - enkephalin.

Differences in the degradation of hypothalamic releasing factors by rat and human serum.

Metabolic instability of myelin proteins. Breakdown of basic protein induced by brain cathepsin D.

Breakdown of somatostatin and substance P by cathepsin D purified from calf brain by affinity chromotography