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Heterogeneit of renin and renin-substrate
exampte: conceplf ati to be developed in a ‘meaningful manner*. ‘the theory of mea+ urement. cenain arithmetical properties of measures are impormnt. and applicable taxonomiesreflecl th2t focus’. ‘we havejust identif’icda particular kind of con&it% ratio situation’. ‘a probabilily density function.. however, is the mathelnatical representa tion of a continuous r;indom variable and thus is a anon poft*rrtialoutcome situ&on*, ‘a set of empirical observationscontrials of a ranceptualizd . . . as rep3ed dom variable situation’. *a random variable that is mathematically cuncepWiz.ed in ~~jn~~ with a given set of data. for example, a random vtible conceptualized as the “generator”’ of ,xtr IO0 empirical mc*urti, is sometime+ refened to as an underlying random vziable’. It is, of cotmse, rtot quite fair to quote the= past saps out of context, but were the last LWO really clearer than something like: *a set of WJ tirvations can be thoughtof a.+being
sekxted at random from a popuk3tian of
Discussingrenin
ciency of cst~m5to~ sewms quite inapproLanguage apart. the choice of subject matter also rSvorries me. It is admirable to discuss discrete and continuous variables. mobility and probability density. But why on earth spend many pugs discussing higher moments (with a table to illuslrate calcJatiott of rhird, fourth and fifth moments) under the rather unhelpful head. irtg ‘The v,ariancxz and other averages’; having spent much time ott this it is then neces. spry to point out later that ‘for many kinds of probability distribution, there will he simpler ways of dcfming lhese paramettitally than by using the fuil set of the it&it&e number of moments’. This fcems to me to he a rather pedantic throwback to a somewhat old-fashioned theoretical presentation of disxibutions; certainly it seemsquite out of place hen!. The usesof fifth moment5 in behaviour31(or any other) sciencesare distinctly limited. Likewise, a description (though brief and. inevitably. incotnprehensiblej of the efficiency and suffc
priate. It is this sort of thing that makes me dub&s sbo tt the verbal explanation. of which most d the book consists.The book does not claim to teach methods. and this is true. For c~j:mple. although the book is ‘for the beh;avicJlratsciences’ there are Z-3 pages 011t1.e corxlalion coefficient, and chi-sqtxed is described only in ti context of the ~~i~~j~utio~~ ofthe sampfe variance. A book that made clear the ideas that underliz sta&tical arguments, whether or not it s-aid ntuch about methods, would he very adcot?e_ 1 agree with the author that most klooks are boringly similar. and not very axces~sful. His book is certainly different. and the only way to tell whether it will be any more successfulthan the others would be to try it out on students.Perhapsit will be but I doubt it.
Boucher., who had a&ed in his last years a new dimension to the intricacies of angiotcntC fmatinn. He and his col+ leagues had described, named. putif&, characterized and even sequenced ronin. an enzyme so far found in salivary and pituitary glands and in the brain, which forms All. witltaut the intervemion of r&n. The tntrcduction and the tanin review are gathered under the heading l Angiotertsinogenases’. a term more cumbersome than precise: it evidently includes tonin which atzacks AI as welt as ar~gjote~ sinogen; it is presumably not intended for those proteases which digest angioten sinogen u’ilbout releasing AI or All. The remaining six sections contain 39 ~~~~t~on~ giving useful detail on th form&xl, release and properties of ret&s and of thcit substrates.Let me point out the newer aad more controversial issuesin the contents. K. Pot&en’s elegant work in which renal and s~~~bul~ mRNA was translat&~suggeststhat at this step a single peptide chain pre-praren+ is synthesized consisting of a sign& a precursor and an a&w renin pan. E. Haber’s group, whir unt11 recently viewed ‘through a glass dar’i:j’ the concept of a renin precursor. BOW stt~i& suppmt it, and this view is shared by several other groups_ T%e enzymes which in v&o activate the precrzSor are still uflcerlain, &hough nuinerr~us clotting and fibrinolytic factors and k&ikreins can do so in :vimo . Renin activatran may be reversible. which raises the possi bil.ity hat renins may oecttr not only as prei%rsors. hut also in latent fan-n. Circulating inhibiiors rich in lipids my contribute to
this phcenomenon.Modern protein chemistry separW:s not only multiple forms of renins %tt also of a~giotens~noge~. and the comlx&tir>n rrf both is under hormonal and other influences. D. H. Dsmond and colleague+ even describe a prsangiotensinogen p -ematurely released from the liver becauseof sub&ate loss throughconrinuou?; amt~~ulatary peritoneal dialysis (CAPI)). Renin-like enzymes from brain. vascular and other tissues may remain cell-hound
l
complicaresthe kinetics of AI formation.
To concl~ude the list of emerging concepts: renin secretion is inhibited by dopaminergic Wbres;glomeruli produce an AI convertit~genzyme; activation of inac tive renin is enhanced by low tubular sodium levels, but not by other stimuli of
renin secretion. Alf those actively interestedin this fiiid
sekxted at random from a popuk3tian of
Discussingrenin
ciency of cst~m5to~ sewms quite inapproLanguage apart. the choice of subject matter also rSvorries me. It is admirable to discuss discrete and continuous variables. mobility and probability density. But why on earth spend many pugs discussing higher moments (with a table to illuslrate calcJatiott of rhird, fourth and fifth moments) under the rather unhelpful head. irtg ‘The v,ariancxz and other averages’; having spent much time ott this it is then neces. spry to point out later that ‘for many kinds of probability distribution, there will he simpler ways of dcfming lhese paramettitally than by using the fuil set of the it&it&e number of moments’. This fcems to me to he a rather pedantic throwback to a somewhat old-fashioned theoretical presentation of disxibutions; certainly it seemsquite out of place hen!. The usesof fifth moment5 in behaviour31(or any other) sciencesare distinctly limited. Likewise, a description (though brief and. inevitably. incotnprehensiblej of the efficiency and suffc
priate. It is this sort of thing that makes me dub&s sbo tt the verbal explanation. of which most d the book consists.The book does not claim to teach methods. and this is true. For c~j:mple. although the book is ‘for the beh;avicJlratsciences’ there are Z-3 pages 011t1.e corxlalion coefficient, and chi-sqtxed is described only in ti context of the ~~i~~j~utio~~ ofthe sampfe variance. A book that made clear the ideas that underliz sta&tical arguments, whether or not it s-aid ntuch about methods, would he very adcot?e_ 1 agree with the author that most klooks are boringly similar. and not very axces~sful. His book is certainly different. and the only way to tell whether it will be any more successfulthan the others would be to try it out on students.Perhapsit will be but I doubt it.
Boucher., who had a&ed in his last years a new dimension to the intricacies of angiotcntC fmatinn. He and his col+ leagues had described, named. putif&, characterized and even sequenced ronin. an enzyme so far found in salivary and pituitary glands and in the brain, which forms All. witltaut the intervemion of r&n. The tntrcduction and the tanin review are gathered under the heading l Angiotertsinogenases’. a term more cumbersome than precise: it evidently includes tonin which atzacks AI as welt as ar~gjote~ sinogen; it is presumably not intended for those proteases which digest angioten sinogen u’ilbout releasing AI or All. The remaining six sections contain 39 ~~~~t~on~ giving useful detail on th form&xl, release and properties of ret&s and of thcit substrates.Let me point out the newer aad more controversial issuesin the contents. K. Pot&en’s elegant work in which renal and s~~~bul~ mRNA was translat&~suggeststhat at this step a single peptide chain pre-praren+ is synthesized consisting of a sign& a precursor and an a&w renin pan. E. Haber’s group, whir unt11 recently viewed ‘through a glass dar’i:j’ the concept of a renin precursor. BOW stt~i& suppmt it, and this view is shared by several other groups_ T%e enzymes which in v&o activate the precrzSor are still uflcerlain, &hough nuinerr~us clotting and fibrinolytic factors and k&ikreins can do so in :vimo . Renin activatran may be reversible. which raises the possi bil.ity hat renins may oecttr not only as prei%rsors. hut also in latent fan-n. Circulating inhibiiors rich in lipids my contribute to
this phcenomenon.Modern protein chemistry separW:s not only multiple forms of renins %tt also of a~giotens~noge~. and the comlx&tir>n rrf both is under hormonal and other influences. D. H. Dsmond and colleague+ even describe a prsangiotensinogen p -ematurely released from the liver becauseof sub&ate loss throughconrinuou?; amt~~ulatary peritoneal dialysis (CAPI)). Renin-like enzymes from brain. vascular and other tissues may remain cell-hound
l
complicaresthe kinetics of AI formation.
To concl~ude the list of emerging concepts: renin secretion is inhibited by dopaminergic Wbres;glomeruli produce an AI convertit~genzyme; activation of inac tive renin is enhanced by low tubular sodium levels, but not by other stimuli of
renin secretion. Alf those actively interestedin this fiiid