( ( ( ( ( ( ( ( ( ( ( ( ( Several proximal ) ( tubular functions ) ) -- ) ( ( maximal excretion ) ( of p ) ) ) - ) ( ( ( aminohippurate ( and ( ( iodopyracet and ) maximal ) ) ) absorption ) ( of glucose ) ) ) -- ) ( parallel ( the decline ) ) ) ( ( in ( glomerular filtration ) ) rate ) ) , ) ( suggesting ( that ( ( tubular function ) ( disappears ( in ( entire nephrons ) ) ) ) ) ) ) ( with age ) ) . )
(ROOT (NP (NP (NP (NP (JJ Several) (NN proximal)) (NP (JJ tubular) (NNS functions))) (: --) (NP (NP (JJ maximal) (NN excretion)) (PP (IN of) (NP (NN p)))) (: -) (NP (NP (ADJP (JJ aminohippurate) (CC and) (JJ iodopyracet) (CC and) (JJ maximal)) (NN absorption)) (PP (IN of) (NP (NN glucose)))) (: --) (NP (NP (NN parallel)) (NP (DT the) (NN decline)))) (ADJP (PP (IN in) (NP (NN glomerular) (NN filtration))) (NN rate)) (, ,) (VP (VBG suggesting) (SBAR (IN that) (S (NP (JJ tubular) (NN function)) (VP (VBZ disappears) (PP (IN in) (NP (JJ entire) (NNS nephrons))))))) (PP (IN with) (NP (NN age))) (. .)))
Several proximal tubular functions--maximal excretion of p -aminohippurate and iodopyracet and maximal absorption of glucose--parallel the decline in glomerular filtration rate, suggesting that tubular function disappears in entire nephrons with age.
(ROOT (S (NP (NP (DT The) (JJ main) (NNS functions)) (PP (IN of) (NP (NN epithelia)))) (VP (VBP are) (NP (NP (NN protection)) (PP (IN from) (NP (NP (DT the) (NN environment) (, ,) (NN coverage) (, ,) (NN secretion) (CC and) (NN excretion)) (, ,) (NP (NN absorption)) (, ,) (CC and) (NP (NN filtration)))))) (. .)))